call for vs cross one's fingers

call for

verb
  • To stop at a place and ask for (someone). 

  • To shout out in order to summon (a person). 

  • To ask for in a loud voice. 

  • To request, demand. 

  • To necessitate, demand. 

cross one's fingers

verb
  • when wishing for luck, or 

  • when telling a lie (and attempting to escape the moral and other consequence of that lie). 

  • To put the middle finger across the index finger, especially 

How often have the words call for and cross one's fingers occurred in a corpus of books? (source: Google Ngram Viewer )